Electric regulator



Feb. 12, 1946. w A CRQTCH ELECTRIC REGULATOR Filed Dec. 13, 1943 3SheetsSheet 1 Feb. 12, 1946. w. A. CROTCH ELECTRIC REGULATOR Filed Dec.13, 1943 3 Sheets-Sheet 2 Feb. 12, 1946. w, A. g H 2,394,753

ELECTRIC REGULATOR Filed Dec. 13, 1943 3 Sheets-Sheet 3 or two or moresymmetrically arranged piles.

Patented Feb. 12, 1946 ELECTRIC REGULATOR William Albert Crotch,Orpington, England, assignor to ,1. Stone & Company Limited, Deptford,England, a British joint-stock company Application December 13, 1943,Serial No. 514,167 In Great Britain December 16, 1942 8 Claims.

This invention comprises improvements in electric regulators of thecarbon pile type. In a regulator of this type there may be a single pileIn the case of a single pile, it is essential that the pressure plate,applying pressure at one end of the pile, should be operated in such amanner that it will apply the pressure equally over the surface area ofsuch end of the pile. In the case of two or more piles, it is importantthat the beam or yoke applying pressure to the several piles shouldoperate in such a manner as to ensure an equal distribution of pressureto the several piles. It is, furthermore, of importance that theaforesaid equalization of pressure, or equal distribution of pressure,should be reliably maintained throughout the range of operation of a,regulator and regardless of whether maximum or minimum pressure or zeropressure is being applied to the pile or piles.

It has been sought to secure the desired effect by providing a stiff orsticky ball joint Or joints between the rod, lever, beam or yoke and thepressure plate employed for transmitting the pressure to the pile orpiles. The stickiness of this joint was intended to preserve theparallelism of a pressure plate with the discs of the pile under minimumor zero pressure conditions. Under higher pressure, or maximum pressureconditions, the stickiness of the joint was overcome by the forcesarising so that the pressure plate could satisfactorily adjust itself inrelation to the pile. It has been found, however, that when the effectsof vibration must be taken into account, if the ball joint is madesufliciently tight or sticky for reliable service under minimum pressureconditions, the dange arises that the forces developed under increasedpressure conditions may be insufiicient for overcoming the stickinessand producing a resetting of the joint such as may be necessary forequalizing the distribution of pressure. It has to be remembered that acarbon pile, under maximum working pressure, does not constitute a rigidabutment. Consequently, if there is an appreciable frictional torque onthe joint when pressure i applied this will cause an out of balanceefiect either in the application of the pressure to a single pile, or inthe distribution of such pressure over several piles.

According ,to the present invention jointing mean in the pressureapplying systemof a reg-' ulator of the carbon pile type are socontrived that under higher and maximum pressure conditions. frictionaltightness is ubstantially or wholly removed from the joint, but isrestored during the lower part of the pressure range or when pressure isremoved; By this means, the joint is perfectly free to set itself foraccurate parallelism or alignment during the upper part of the pressurerange but is sufliciently'stiff to maintain the desired conditionsduring the lower part, or at the bottom, of the pressure range in spiteof vibrational effects. By these improvements, it is possible to arrangefor the joint to have great stiffness at zero pressure on the pile sothat it cannot possibly be shaken out of position by vibration, andnevertheless to be substantially free of frictional stiffness in theupper part of the pressure range.

In order to enable the invention to be readily understood, reference ismade to the accompanying drawings wherein:

Figure 1 illustrates, in central vertical section, theinvention asapplied between the magnetoperated system of an electric regulator and asingle pile composed of superposed carbon rings.

Figure 2 is a plan of Figure 1.

I Figure 3 is a central vertical section, the plane of this sectionbeing at right angles to that of Figure 1.

Figure 4 is a side elevation illustrating the invention as appliedbetween the magnet-operated system of an electric regulator and threecarbon piles symmetrically disposed around a centre.

Figure '5 is a sectional elevation, the section being taken on the lineVV of Figure 4 and as seen when looking towards the left hand.

Figure 6 is a sectional elevation, the section bein taken on the lineVI-VI in Figure 5 and as seen when looking towards the right hand.

Figure 7 is a plan section taken on the line VII-VII of Figure 6.

Figure 8 is a sectional elevation, the section being taken on the lineVIII-VIII of Figure 7 and as seen when looking towards the left hand.

Figure 9 is a diagrammatic elevation illustrating the invention inslightly modified form as applied between the magnet-operated system ofan electric regulator and two carbon piles disposed apart, and

Figure 10 is a sectional view of the joint parts, the section being onthe line X-X of Figure 9.

Referring to Figures 1 to 3, a represents the carbon pile of an electricregulator, the said pile consisting of superposed carbon rings with acollector ring bat the top surmounted by a presser ring "0. The latteris formed with a diametral cross bar to which is jointed an axial rod dwhich is connected with the magnet-operated system of the regulator.Usually, a loading spring is operative for depressing the rod d andthereby causing the presser ring 0 to apply maximum compression to thepile a. When the electro-magnet of the regulator becomes sufiicientlyenergized it operates against the loading spring to lift the rod (2 andthereby to reduce the compression of the pile and increase pileresistance. The up and down movement of which the rod d is capable, isindicated by the double headed arrows in Figures 1 and 3. Now, the jointprovided by the present improvements between the rod d and the ring 0 isconstructed as follows: The lower end of the rod d is forked and betweenthe prongs d of the fork a small block e is fixed, as by means of therivets f. The block e is formed with a part spherical surface 6presented upwardly in Figures 1 and 3 and with a flat surface 6presented downwardly. Thus, the block e may be a half sphere but withflats formed parallel with a diameter such flats being engaged by theflat inner faces of the prongs d as shown in Figures 2 and 3. The crossbar 0 is divided in the middle and its divided ends are formed as apartially spherical seating for engaging upon the part spherical surfacee of the block e, as seen clearly in Figures 1 and 2. In each of thedivided parts of the cross bar 0 there is fixed a small bolt or pin 9extending downwardly within the pile. The pins g guidingly support ayoke h, the latter having perforated ends slidingly engaging the pins 9.In the middle of its length the yoke h is formed with a dimple providingan upwardly projecting point h which engages with the flat lower surface6 of the block e at its pivotal centre. Springs 7' coiled around thepins 9 exert upward pressure against the yoke h and keep the point 72hard against the block 6 and the compression of the springs '1' isadjustable to a desired value by means of the nuts 70 on the ends of thepins 9.

The operation is as follows: When the rod (1 is fully depressed by theloading spring of the regulator for putting the pile a under maximumcompression, such compression is applied by the block e depressing theyoke h and thereby putting the springs 7' under additional compression.The downward effort of the springs 7' on the pins g is thus imparted tothe presser ring 0 for putting the pile a under maximum compression. Indepressing the yoke it against the actioniof the springs 11, the block 6eases or loosens its spherical surface e from engagement with theconical seating surfaces on the divided ends of the cross bar 0 so thatthe pivotal joint is now very easy and non sticky. The degree of easingor loosening, of course, corresponds with the degree to which thesprings y are additionally compressed by the depression of the rod d.The presser ring 'c is thus quite free to adjust itself upon the pile aso as to apply pressure equally at all points around the pile rings.This self-adjusting movement is practically a universal movement, first,because the yoke 71. has only a point engagement with the flat surface 6of the block e and, second, because the spherical surface of the block eand the conical seating in the divided ends of the bar 0 form a speciesof ball or universal joint. When the electro-magnet of the regulatorovercomes the loading spring, the rod d rises a little and the block 'epermits the yoke h to rise under the influence of the springs 9'. Thelatter thus become effective for tightening the ball joint be tween thespherical surface e and its conical seating in the divided ends of thecross bar c The progressive effect therefore, is as follows: As theelectro-magnet commences to overcome the spring loading and the rod drises a little the ball joint is tightened a little but still permitsthe presser ring 0 to adjust itself to the pile a under the appreciableinherent expanding force of such pile. If the electro-magnet strengthensso as to overcome still further the spring loading, the ball joint isfurther tightened being still in a position in which it engages squarelyand evenly on the end of the pile, the expanding force of the latterbeing by then considerably reduced. With further strengthening of theelectro-niagnet further tightening of the ball joint and furtherdecompression of the pile occur until maximum de-compression of the pilea is reached. In this condition, the pile has no expanding force but thepresser ring 0 is retained evenly or squarely against the end of thepile by the ball joint which is now in a still or sticky condition dueto the action of the springs 1.

The stiffness or stickiness of the joint is such that the retention ofthe presser ring 0 in the condition described is preserved in spite ofviolent vibrations to which the regulator may be subjected, as wheninstalled on an aircraft or a railway vehicle. Preferably, the springs jare initially adjusted so that their combined force is about equal tothe maximum compression force applied to the rod 11. With thisadjustment, the ball joint is quite free when the pile a is undermaximum compression, although it is very tight and sticky when the pileis deconipres'sed.

Figures 4 to 8 illustrate a construction comprising three piles a a anda disposed apart, each pile being composed of carbon rings supported byacentral non-conductive sleeve 1 on a core rod m. At the right hand end,in Figures 4 and 6, the piles a a bear against a rigid abutment on theframing of the regulator in known manner. At the left hand end, eachpile is pressed against by a presser ring 11 formed with two lugs nFigure 5, for enabling it to be secured by screws 0 to lugs of a presserplate 1). The latter is jointed with and operated by a bar q which issupported by having each end bolted 1 to a springy diaphragm plate 1'.This method of mounting the bar q "ensures that it has a, substantiallystraight line movement parallel with the piles in either direction. Thediaphragm plates r as seen in Figure 5, are cut out from sheet metal soas to be of skeleton formation to give maximum springiness and so as tohave perforated lugs r by means of which they can be bolted to frameparts of the regulator. Atom end, the bar q is bent to form one integralprong (1 a companion prong q having its shank secured by a bolt q to thebar q. Various known means may be adopted for transmitting to the bar qthe regulating movements due to the regulator magnet overcoming more orless the loading spring which puts the piles under compression. InFigure 4, the means comprises a twoarmed lever s pivoted at s in abracket on the regulator framing, a metal tape it having one endattachedto one arm of. the lever s and the other end attached to the barq, as by means of the clamping bolt q Figure 6, The other arm of thelever s in Figure 4 is swingable as indicated by the double headedarrow, the leftward swing being produced by the loading spring (notshownfor compressing the piles and the rightward swing being produced by the,electro-magnet (not shown) which overcomes more or less the effort ofthe loading spring in known manner.

Between the prongsq q there is secured by rivets a block 6 preciselysimilar to the block e of Figures 1 to 3, this block e, as seen clearlyin Figures 6 to 8, having a spherical surface e and a flat surface e Thespherical surface is engaged or seated by lugs 10 struck up from theplate p, the ends of these lugs p being coned so that each limb has anappropriate bearing upon the spherical surface e Thisis the sameconstruction as illustrated in Figure 2, wherein the divided ends of thebar c are formed so as to provide a conical seating for the sphericalsurface of the block 6. On the plate 10 are fixedly mounted two pins 9guidingly supporting a yoke h, the latter being formed with a dimple toprovide a, point h for bearing against the flat face 6 of the block e atitspivotal centre. The yoke h is pressed against the block e bycompression springs a, the compression of these springs being adjustableby nuts k as in Figures 1 to 3. The action of the joint is similar tothat already described with reference to Figures 1 to 3 but in Figures 4to 8 the joint enables the presser plate p to adjust itself universallyso as to apply pressure equally to all three piles a a and a When thepiles are under maximum compression due to clockwise turning of thelever s, Figure 4, the joint i loose and free because, a will beunderstood from Figures 6 to 8, the block e is forced against the yoke hand loosens itself in its seating in the lugs p when the yoke h recedesand further compresses the springs a. When the lever s turnscounterclockwise to decompress the pile, the spherical surface e of theblock e is re-tightened in its seating against the lugs 11 underpressure of the springs 7' applied through the yoke h. In all otherrespects, the action of the joint in Figures 4 to 8 is similar to thatdescribed with reference to Figures 1 to 3.

Figures 9 and 10 illustrate more or less diagrammatically a twin pilearrangement for a regulator, some of the parts being similar to thosedescribed with reference to Figures 4 to 8. For example, the two piles aa which are spaced 180 apart are pressed against at one end by presserrings 11, secured by screws to a presser plate 1). The plate 11 isjointed to a bar q which is supported for movement parallel with thepiles by diaphragms in this case represented as conventional corrugateddiaphragms 1 In Figure 9, the piles a a are shown with their right handends rigidly abutted against a frame plate u. The bar q has attached toit one end of a metal strip t, the opposite end (shown with a hole inFigure 9) being attachable to means such as the lever 3 described withreference to Figure 4. The bar q comprises a detachable prong q which isattached to it by means of a bolt 11 as described with reference toFigure 6. The modification of the joint in Figures 9 and consiststhereinthat the block e is a semi-cylindrical block and not apart-spherical block as in the preceding figures, and that the yoke h isbent to form a knife edge It for bearing against the fiat surface of theblock e at the pivotal axis of the block, this knife-edge bearing takingthe place of the point bearing 71. of the preceding figures. The factthat the block e is semi-cylindrical can be seen from Figure 10 whereinthe edges bounding the upper and lower sides of the block as seen inthat figure are straight and not curved. The block e like the block e inFigures 4 to 8, is

adapted for seating against lugs 10 struck up from the plate p only inthis modification the ends of such lugs are formed with flat faces setat an angle for fitting against the cylindrical surface of the block eThe yoke h is pressed against the flat surface of the block c by springs1i coiled around pins g on the plate 10, the springs 9' being adjustableas to compression by means of the nutslc as in Figures 4 to 8. It willnow be apparent, without further description, that the pivotal jointbetween the block :2 and the lugs p is eased or loosened when the bar qoperates the plate p for applying maximum compression to the piles a aand that the said joint is tightened so as to become sticky asdecompression of the piles proceeds under electro-magnetic action. Thereason that the block e may be cylindrical instead of spherical and thatthe yoke h may have a knife edge bearing it against the block instead ofa point bearing, is that the plate p needs only freedom to make asee-saw motion in order to distribute compressive force equally to thetwo piles a a disposed 180 apart. 1

In all constructions, the spherical or cylindrica surface of the block eor e is made of adequate radius and the seating faces of the parts 0 orp engaging it are given such a suitable formation or angular settingthat the force available from the spring loading of the yoke plate It orh produces a pivotal joint which is very firm or sticky when the effortexerted by the rod or bar d or q is minimum.

I claim:

1. In an electric regulator of the carbon pile type, a carbon pile, apressure-applying system operative for compressing the carbon pile,presser means engaging the pile, and a friction-tight pivotal jointbetween said presser means and the pressure-applying system, said jointhaving means for easing the friction tightness thereof upon transmissionof maximum compression forces thereto and for restoring said frictionaltightness as the compression forces applied thereto are reduced.

2. A regulator as claimed in claim 1 and in which said pressure-applyingsystem includes a bar, the presser means being formed with a joint seat,a block having a rounded surface located between the presser means andsaid bar, said rounded surface being adapted for making joint with theseat of said presser means, said block being fixedly mounted on saidbar, and a springloaded yoke mounted on said presser means and pressingsaid block towards its seat.

3. A regulator as claimed in claim 1 and in which said pressure-applyingsystem includes a bar, the presser means being formed with an angularjoint seating, a block having a cylindrical surface located between thepresser means and said bar, said cylindrical surface being adapted formaking joint with the seat of said presser means, said block beingfixedly mounted on said bar and also having a flat surface, and a aspring-loaded yoke mounted on said presser means and pressing said blocktowards its seat, said yoke being formed with a knife-edge projectionengaged by the said flat surface of said block.

4. A regulator as claimed in claim 1 and in which said pressure-applyingsystem includes a bar, the presser means being formed with an angularjoint seating, a block having a spherical surface located between thepresser means and said bar, said spherical surface being adapted formaking joint with the seat of said presser means, said block beingfixedly mounted on said bar and also having a flat surface, and aspringloaded yoke mounted on said presser means and pressing said blocktowards its seat, said yoke being formed with a pointed projectionengaged by the said flat surface of said block.

5. A regulator as claimed in claim 1 and in which said pressure-applyingsystem includes a bar, the presser means being formed with a joint seat,a block having a rounded surface located between the presser means andsaid bar, Said rounded surface being adapted for making joint with theseat of said presser means, said block being fixedly mounted on saidbar, a springloaded yoke mounted on said presser means and pressing saidblock towards its seat, and means for adjusting the spring loading ofthe yoke.

6. In an electric regulator of the carbon pile type, a carbon pile, acollector for applying pressure to the carbon pile to vary itselectrical resistance, actuating means for the regulator, a jointbetween said actuating means and the co1- lector, said joint including aseat facing in the general direction of the collector considered withrespect to the direction of transmission of forces tending to compressthe pile, a block for frictionally engaging said seat, said block beingconnected with the actuating means so that the actuating means tends tomove the block away from the seat and reduce the friction therebetweenupon increase of force tending to compress the pile to enable said blockto adjust itself relative to said seat upon increase of said force, andmeans for yieldingly connecting said block to the collector to transmitsaid force thereto.

7. In an electric regulator of the carbon pile type, a carbon pile, apressure-applying system operative for compressing the carbon pile,presser means engaging the pile, a pivotal joint between said pressermeans and the pressure applying system, and resilient means interposedbetween said presser means and said system and constantly tending tomaintain friction tightness in said pivotal joint, said system beingconnected with a member of said joint as to oppose the tendency of saidresilient means when said systern is operative for producing compressionof said pile.

8. In an electric regulator of the carbon pile type, a carbon pile,presser means engaging one end of said pile, a pressure applying systemoperative for controlling the compression of said pile, a pivot jointmember connected with said system, a cooperative pivot joint member onsaid presser means, and spring means constantly tending to maintainfriction tightness between said joint members but in opposition to saidsystem when the latter is operative in the direction for compressingsaid pile.

WILLIAM ALBERT CROTCH.

